javascript - 缺少必需参数 - public_id，以及为 Cloudinary 分配给 imageId 的内容

Question

我正在建立一个网站，用户可以上传对阅读小说的见解和评论，用户可以自由地获取或不获取小说的图像。

如果选择图像，则帖子模式具有用于 Cloudinary 上传和 future 操作的 image 和 imageId 属性，例如从 Cloudinary 库更改(更新路由)或删除(销毁路由)它。如果未选择图像，则会出现默认图像。

问题是，我设法使 default image 功能正常工作，但是我不想将多个相同的默认图像上传到 Cloudinary 库，因此我将 default_image.jpg 放在本地服务器文件夹 (/public/images) 中，准确地说，这个 default_image.jpg 不应该在 Cloudinary 库中，这应该节省大量容量。

但是，对于这些没有选择图像的帖子，我不知道应该为其 imageId 属性分配什么。

我尝试了 undefined 和 null，当然，它们不起作用，因为这样，如果它们都未定义或为 null，它将无法找到某些 novel.imageId。

// Schema for data
var fictionSchema = new mongoose.Schema({
    ...
    ...
    image: String,
    // for cloudinary API to track which image to delete or update
    imageId: String,
    ...
    ...
});

// CREATE route
router.post("/", middleware.isLoggedIn, upload.single('image'), (req, res) => {
    if (req.file){
        // req.file.path comes from multer npm
        cloudinary.v2.uploader.upload(req.file.path, function (err, result) {
            if (err) {
                ...
            }
            // add cloudinary url for the image to the novel object under image property
            req.body.novel.image = result.secure_url;
            req.body.novel.imageId = result.public_id;
        });
    } else {
        // setup default image for new novels
        req.body.novel.image = "/images/noimage.jpg";

        // imageId here should be ... empty? Undefined? Null? A fixed ID but may be delete when accessing Destroy route?
        req.body.novel.imageId = undefined;
    }
    ...
    ...
    Novel.create(req.body.novel, function (err, newlyAddedNovel) {
        if (err) {
            req.flash('error', err.message);
            ...
        } else {
            req.flash("success", "Novel added successfully.");
            ...
        }
    });
});

// DESTROY route
router.delete("/:id", middleware.checkNovelOwnership, (req, res) => {
    // find and delete the correct novel along with the image on cloudinary
    Novel.findById(req.params.id, async (err, novel) => {
        if (err) {
            req.flash("error", err.message);
            return res.redirect("back");
        }
        try {
            await cloudinary.v2.uploader.destroy(novel.imageId);
            // delete the novel found
            novel.remove();
            // delete the image from cloudinary
            req.flash("success", "Novel deleted successfully.");
            ...
            ...
        } catch (err) {
            ..
        }
    });
});

Answer 1

好消息，我解决了这个问题!她——雷!不过花了我大约2个小时...

所以，最终一切都按照我想要的方式进行，如此巧妙。

代码如下:

• 创建路线

对于新帖子，我首先使用默认图像设置每本新小说，然后如果提供了图像(req.file)，则更改它并上传。

然后，记得在 mongo 数据库中创建新数据。 (在我的例子中是Novel.create()。)

router.post("/", middleware.isLoggedIn, upload.single('image'), async function (req, res) {
    // set every new novel with default image first
    req.body.novel.image = "https://res.cloudinary.com/dvfkbz6la/image/upload/v1565434656/noimage_ew1uri.jpg";
    req.body.novel.imageId = "noimage_ew1uri";
    req.body.novel.user = {
        id: req.user._id,
        username: req.user.username
    };

    if (req.file) {
        // req.file.path comes from multer npm
        await cloudinary.v2.uploader.upload(req.file.path, function (err, result) {
            if (err) {
                req.flash('error', err.message);
                return res.redirect('back');
            }
            // add cloudinary url for the image to the novel object under image property
            // add image's public_id (imageId in novel model) to novel object
            req.body.novel.image = result.secure_url;
            req.body.novel.imageId = result.public_id;
        });
    }
    Novel.create(req.body.novel, function (err, newlyAddedNovel) {
        if (err) {
            ...
        } else {
            ...
        }
    });
});

• 更新路线

在try block 中添加if (novel.imageId = "DEFAULT_IMAGEID") { } else { }。

// UPDATE route
router.put("/:id", middleware.checkNovelOwnership, upload.single('image'), (req, res) => {
    // find the correct novel
    Novel.findById(req.params.id, async (err, novel) => {
        if (err) {
            ...
        } else {
            // if there's a req.file, we know user is trying to upload a new image
            if (req.file) {
                try {
                    // if imageId is default, await the result to be uploaded
                    if (novel.imageId = "noimage_ew1uri") {
                        var result = await cloudinary.v2.uploader.upload(req.file.path);
                    } else {
                        //  if not default, find the old image using imageId and delete
                        await cloudinary.v2.uploader.destroy(novel.imageId);
                        var result = await cloudinary.v2.uploader.upload(req.file.path);
                    }
                    novel.imageId = result.public_id;
                    novel.image = result.secure_url;
                } catch (err) {
                    ...
                }
            }
            novel.title = req.body.title;
            novel.author = req.body.author;
            novel.price = req.body.price;
            novel.description = req.body.description;

            // remember to save the changed novel
            novel.save();
            req.flash("success", "Successfully Updated!");
            res.redirect("/novels/" + novel._id);
        }
    });
});

• 摧毁路线

在try block 中添加if (novel.imageId != "DEFAULT_IMAGEID") { } else { }。

// DESTROY route
router.delete("/:id", middleware.checkNovelOwnership, (req, res) => {
    // find and delete the correct novel along with the image on cloudinary
    Novel.findById(req.params.id, async (err, novel) => {
        if (err) {
            req.flash("error", err.message);
            return res.redirect("back");
        }
        try {
            // if novel.imageId isn't default, destroy it from Cloudinary
            if (novel.imageId != "noimage_ew1uri") {
                await cloudinary.v2.uploader.destroy(novel.imageId);
            }
            // delete the novel found
            novel.remove();
            ...
        } catch (err) {
            ...
        }
    });
});

<小时/>

剩下的唯一问题是，我不知道为什么，但是当点击更新路线时，当 imageId 不是默认的并且用户更改了图像时，

旧镜像不会被销毁并保留在 Cloudinary 库中。真是奇怪。

我确实设置了此代码

Novel.findById(req.params.id, async (err, novel) => {
        if (err) {
            ...
        } else {
            if (req.file) {
                try {
                    // if imageId is default, await the result to be uploaded
                    if (novel.imageId = "noimage_ew1uri") {
                        ...
                    } else {
                        //  if not default, find the old image using imageId and delete
                        await cloudinary.v2.uploader.destroy(novel.imageId);
                        var result = await cloudinary.v2.uploader.upload(req.file.path);
                    }
...
...

不知道为什么等待 cloudinary.v2.uploader.destroy(novel.imageId);没有按预期工作。嗯...